The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 21, 1986
Filed:
Jun. 29, 1983
Applicant:
Inventors:
Bruno J Barone, Houston, TX (US);
William G Bowman, Dickinson, TX (US);
Assignee:
Denka Chemical Corporation, Houston, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549256 ; 549262 ;
Abstract
It has been found that phosphoric acid alone and in admixture with phenothiazine and/or methyl-p-benzoquinone reduces residue formed during the fractionation of aqueous crude maleic compositions for the production of maleic anhydride, and in particular, reduces residue due to the presence of small amounts, i.e., less than 10 ppm alkali metal ion. When the alkali metal ion is present at least 9 equivalent acid groups of phosphoric acid per atomic equivalent of alkali metal ion are present.